During a surgical procedure, it can be difficult to maintain a steady frame of reference with respect to the patient tissue within the surgical site. For example, the surgery may modify the patient tissue, the patient tissue may move within the patient's body, blood may obscure the patient tissue, local anatomic conditions may require that the patient tissue may be viewed or manipulated at an awkward angle for the surgeon, or the like. In addition, the patient tissue may be slippery or unstable within the surgical site.
Accordingly, a guide pin or guidewire may be temporarily engaged with the patient tissue and protrude therefrom to provide a landmark to orient the user during the surgical procedure. Particularly when the patient tissue of concern is bony or otherwise able to firmly engage and support a rigid structure, an orthopedic guidewire may be attached to the patient tissue to provide a location orientation relative to the patient tissue.
Additionally, a sufficiently sturdy or rigid guidewire may be used as a primary indexing device to physically guide a tool or prosthetic component to a desired location on the patient tissue, and optionally at a desired trajectory. For example, a reamer could have a center hole (i.e., be a “cannulated” tool) that fits over the rigid guidewire for reaming an area of the patient tissue concentrically surrounding the guidewire at a desired location and trajectory. Similarly, an acetabular impactor could be cannulated to fit over the rigid guidewire for impacting a prosthetic acetabular component into place at a desired location and trajectory.
However, it is possible that the “rigid” guidewire may not be sufficiently rigid to hold a tool or prosthetic component as steady as desired to accurately achieve the desired location and/or trajectory of contact with the patient tissue. It is also possible that the rigid guidewire, a guide pin, or another primary or supplemental indexing device might not be able to be placed directly on, in, or at the desired target patient tissue site because that placement will conflict with other operations that are to be performed in the same, possibly spatially constrained, area.